R: Compute a dissimilarity matrix

diss {amap} | R Documentation

## Compute a dissimilarity matrix

### Description

Compute a dissimilarity matrix from a data set (containing only factors).

### Usage

    diss(x, w=rep(1,ncol(x)) )

### Arguments

`x` | A matrix or data frame containing only factors.
`w` | A vector of weight, by default each variable has got same weight

### Details

Case of N individuals described by P categorical variables: each element (i,j) of the signed similarities array is computed by sommation over the P variables of the contributions of each variable, multiplied by the weight of the variable. The contribution of a given categorical variable is +1 if the individual i and j are in the same class, and is -1 if they are not.

### Value

A dissimilarity matrix.

### Author(s)

Antoine Lucas

### See Also

`Dist`, `pop`

### Examples

    data <-
    matrix(c(1,1,1,1,1
            ,1,2,1,2,1
            ,2,3,2,3,2
            ,2,4,3,3,2
            ,1,2,4,2,1
            ,2,3,2,3,1),ncol=5,byrow=TRUE)

    diss(data)

    ## With weights
    diss(data,w=c(1,1,2,2,3))

[Package amap version 0.8-18 Index]